Parents struggle to appreciate each other and mums regard their kids as more important than partner

The line may sound glib, but a new study of relationships suggests Ellis was right – about men and women at least, if not about furry rodents.

While most men with children who took part in the study named their partner as the most important person in their life, the feeling was not entirely mutual. A significant majority (74.8 per cent) of mothers with children under five chose their offspring as the centre of their world.

The study of 5,000 people carried out by the Economic and Science Research Council (ESRC), also found that mothers were "significantly happier with life than any other group". It could be inferred, the ESRC says, "that children are the primary source of happiness for women rather than a partner".

Men with kids will find little solace in some of the study's other findings. For example, fathers were more likely to complain of a lack of sexual intimacy in the relationship. Confronted with the statement "my partner wants to have sex more than I do", 40 per cent of mothers agreed or strongly agreed with the sentiment compared with just 10 per cent of fathers.

So, which group is happiest in their relationships? The short answer: gay couples, couples without children and couples who bring each other cups of tea in bed or cuddle up on the sofa and watch TV.

Gay people tend to be "happier and more positive" about their relationships than heterosexual couples, the study shows. The only caveat is that homosexual couples are less likely to show their affection in public because they still fear disapproval.

An absence of children also contributes to a couple's overall sense of wellbeing and frequent cups of tea – particularly those served in bed by an adoring other half – push the happy needle firmly into the red. The study found that "simple things" like being served a cup of tea in bed or watching TV together, were more "treasured by couples as examples of intimacy" than more grandiose gestures such as saying 'I love you'.

Here are five acts that made people who took part in the survey feel appreciated by their partner:

Says thank you and notices my achievements.

Buys thoughtful gifts and shows kind gestures – a cup of tea in bed was especially appreciated by mothers.